OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.

This is in response to your email of February 20, 2007, to the Occupational Safety and Heath Administration's (OSHA's) Directorate of Enforcement Programs. As was explained in our interim response letter of May 16, 2007, your inquiry raised complex issues and required additional time for an adequate response. You requested clarification of OSHA's requirements for spray finishing operations, specifically asking if a spray booth is required when the substance being sprayed is water-based paint. Your scenario and questions have been paraphrased below, followed by our responses.

Scenario: Your client has a spray finishing operation that is performed periodically and uses fewer than 18 gallons of chemical product per week. The product being used is a water-based (non-flammable) liquid and has some toxic properties. The employer has performed air monitoring and no employee overexposures to the chemicals were obtained. Currently, this operation is not performed within the confines of a spray booth or a spray area (as defined by 29 CFR 1910.107, Spray Finishing Using Flammable and Combustible Materials), and no overspray accumulation has been detected in the work area in which the operation is performed.

Question 1: Should the determination whether to perform the spray operation in a booth be based on the employee's level of exposure to the hazardous chemicals in the paint or the mere presence of a hazardous chemical in the paint?

Answer 1: For purposes of OSHA's standard at 29 CFR 1910.94(c), which addresses ventilation requirements for spray finishing operations, the determination of whether such activities must be conducted in a spray booth or spray room is based on the presence of a hazardous chemical in the paint. Section 1910.94(c)(2) provides:

(2) Location and Application. Spray booths or spray rooms are to be used to enclose or confine all operations. Spray-finishing operations shall be located as provided in section 201 through 206 of the Standard for Spray Finishing Using Flammable and Combustible Materials, NFPA No. 33-1969.

Also, Section 1910.94(c)(8), Scope, provides:

(8) Scope. Spray booths or spray finishing rooms are to be used to enclose or confine all spray finishing operations covered by this paragraph (c). This paragraph does not apply to the spraying of the exteriors of buildings, fixed tanks, or similar structures, nor to small portable spraying apparatus not used repeatedly in the same location.

Although OSHA routinely requires ventilation when employees are exposed to chemicals at levels that exceed established permissible exposure limits (PELs), the known presence of a health hazard during spray finishing operations is also indicative of the need for spray booth ventilation as required by 29 CFR 1910.94(c)(2). Paragraph 1910.94(c)(2) states that "[s]pray booths or spray rooms are to be used to enclose or confine all operations." The source of the spray-finishing portion of the ventilation standard is the American Standard Safety Code for the Design, Construction, and Ventilation of Spray Finishing Operations, ANSI Z9.3-1971 which states, "[t]his standard is intended to protect the health of personnel from injurious effects of contact with gases, vapors, mists, dusts, or solvents used in, created, released, or disseminated by spray-finishing operations." According to this source standard, it is the presence of a toxic chemical which creates the possibility of injurious effects on employees from contact, thus triggering the requirements for spray booth ventilation.

When employees are exposed to chemicals at levels in excess of any of the established standards under 29 CFR 1910.1000(e), Air Contaminants, ". . .administrative or engineering controls must first be determined and implemented whenever feasible." The primary method used to control employee exposures to inhalation hazards is an adequate ventilation system.

Question 2: Is the employer required to use a spray booth when performing the spray-finishing operation described in the scenario?

Answer 2: There are many chemicals, that while not flammable, may still possess harmful properties that can result in occupational illnesses when inhaled or contacted. Water-based paints and other substances that are not considered flammable are applied in occupational settings through the use of spray application techniques and may present potential health hazards. Therefore, as explained in your scenario, if an employer is performing spray-finishing operations using chemicals that are not flammable, but possess possible inhalation health hazards, then the ventilation requirements of 1910.94(c), Ventilation, would apply.

Your email references an existing memorandum of interpretation by OSHA dated June 9, 1978 identifying the requirement to have a spray booth when water-based paints that contain toxic substances are sprayed. Our answer to your inquiry above is consistent with that interpretation. Your client has made an assessment that no hazardous conditions exist during the spraying of their water-based chemicals. It is imperative the employer document that, during any expected conditions of use (of the water-based chemical) at the worksite, no adverse health effects have been, or could be, experienced by employees. Although the employer would be considered to be in violation of 29 CFR 1910.94(c) for failing to perform painting operations in a spray booth when using paint containing toxic substances, such a violation would be considered de minimis, provided that the hazard assessment has in fact demonstrated that no hazardous health effects could result during the application. De minimis violations are those which have no direct or immediate relationship to safety or health. In such instances, OSHA does not issue citations, but rather a notice that does not require abatement.

Thank you for your interest in occupational safety and health. We hope you find this information helpful. OSHA requirements are set by statute, standards, and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you may consult OSHA's website at http://www.osha.gov.